Calling a function of a deployed contract from node over a WebSocket

Question

I'm trying to call a function in a test contract from Node.js with the below code...

const Web3 = require('web3');
const web3 = new Web3(new Web3.providers.WebsocketProvider('ws://139.59.240.233:8546'));
socket.on('callContract', function(data) {
    var contract = new web3.eth.Contract(JSON.parse(data.abi), data.address);
    var result = contract.call().getWord()
    console.log(result);
});

The contract address is: 0xff58d94fe918c347b325c8b6fcde72d9f32e869d

The abi is:

[{"constant":false,"inputs":[{"name":"newWord","type":"string"}],"name":"setWord","outputs":[{"name":"","type":"string"}],"payable":false,"type":"function","stateMutability":"nonpayable"},{"constant":true,"inputs":[],"name":"getWord","outputs":[{"name":"","type":"string"}],"payable":false,"type":"function","stateMutability":"view"}]

the contract i deployed is:

pragma solidity ^0.4.0;
contract WordContract {
string word = "test";
function getWord() constant returns(string) {
    return word;
}
function setWord(string newWord) returns(string) {
 word = newWord;
 return word;
}
}

The error im getting is TypeError: contract.call is not a function

If i console.log(contract); i get

Contract {
  currentProvider: [Getter/Setter],
  _requestManager:
   RequestManager {
 provider:
  WebsocketProvider {
    responseCallbacks: {},
    notificationCallbacks: [Object],
    connection: [Object] },
 providers:
  { WebsocketProvider: [Function: WebsocketProvider],
    HttpProvider: [Function: HttpProvider],
    IpcProvider: [Function: IpcProvider] },
 subscriptions: {} },
  givenProvider: null,
  providers:
   { WebsocketProvider: [Function: WebsocketProvider],
     HttpProvider: [Function: HttpProvider],
     IpcProvider: [Function: IpcProvider] },
  _provider:
   WebsocketProvider {
 responseCallbacks: {},
 notificationCallbacks:
  [ [Function: requestManagerNotification],
    [Function: requestManagerNotification],
    [Function: requestManagerNotification],
    [Function: requestManagerNotification],
    [Function: requestManagerNotification],
    [Function: requestManagerNotification],
    [Function: requestManagerNotification],
    [Function: requestManagerNotification],
    [Function: requestManagerNotification],
    [Function: requestManagerNotification] ],
 connection:
  W3CWebSocket {
    _listeners: {},
    addEventListener: [Function: _addEventListener],
    removeEventListener: [Function: _removeEventListener],
    dispatchEvent: [Function: _dispatchEvent],
    _url: 'ws://139.59.240.233:8546',
    _readyState: 1,
    _protocol: undefined,
    _extensions: [],
    _bufferedAmount: 0,
    _binaryType: 'arraybuffer',
    _connection: [Object],
    _client: [Object],
    onerror: [Function],
    onclose: [Function],
    onmessage: [Function] } },
  setProvider: [Function],
  BatchRequest: [Function: bound Batch],
  extend:
   { [Function: ex]
 formatters:
  { inputDefaultBlockNumberFormatter: [Function: inputDefaultBlockNumberFormatter],
    inputBlockNumberFormatter: [Function: inputBlockNumberFormatter],
    inputCallFormatter: [Function: inputCallFormatter],
    inputTransactionFormatter: [Function: inputTransactionFormatter],
    inputAddressFormatter: [Function: inputAddressFormatter],
    inputPostFormatter: [Function: inputPostFormatter],
    inputLogFormatter: [Function: inputLogFormatter],
    inputSignFormatter: [Function: inputSignFormatter],
    outputBigNumberFormatter: [Function: outputBigNumberFormatter],
    outputTransactionFormatter: [Function: outputTransactionFormatter],
    outputTransactionReceiptFormatter: [Function: outputTransactionReceiptFormatter],
    outputBlockFormatter: [Function: outputBlockFormatter],
    outputLogFormatter: [Function: outputLogFormatter],
    outputPostFormatter: [Function: outputPostFormatter],
    outputSyncingFormatter: [Function: outputSyncingFormatter] },
 utils:
  { _fireError: [Function: _fireError],
    _jsonInterfaceMethodToString: [Function: _jsonInterfaceMethodToString],
    randomHex: [Function: randomHex],
    _: [Object],
    BN: [Object],
    isBN: [Function: isBN],
    isBigNumber: [Function: isBigNumber],
    isHex: [Function: isHex],
    isHexStrict: [Function: isHexStrict],
    sha3: [Object],
    keccak256: [Object],
    soliditySha3: [Function: soliditySha3],
    isAddress: [Function: isAddress],
    checkAddressChecksum: [Function: checkAddressChecksum],
    toChecksumAddress: [Function: toChecksumAddress],
    toHex: [Function: toHex],
    toBN: [Function: toBN],
    bytesToHex: [Function: bytesToHex],
    hexToBytes: [Function: hexToBytes],
    hexToNumberString: [Function: hexToNumberString],
    hexToNumber: [Function: hexToNumber],
    toDecimal: [Function: hexToNumber],
    numberToHex: [Function: numberToHex],
    fromDecimal: [Function: numberToHex],
    hexToUtf8: [Function: hexToUtf8],
    hexToString: [Function: hexToUtf8],
    toUtf8: [Function: hexToUtf8],
    utf8ToHex: [Function: utf8ToHex],
    stringToHex: [Function: utf8ToHex],
    fromUtf8: [Function: utf8ToHex],
    hexToAscii: [Function: hexToAscii],
    toAscii: [Function: hexToAscii],
    asciiToHex: [Function: asciiToHex],
    fromAscii: [Function: asciiToHex],
    unitMap: [Object],
    toWei: [Function: toWei],
    fromWei: [Function: fromWei],
    padLeft: [Function: leftPad],
    leftPad: [Function: leftPad],
    padRight: [Function: rightPad],
    rightPad: [Function: rightPad],
    toTwosComplement: [Function: toTwosComplement] },
 Method: [Function: Method] },
  clearSubscriptions: [Function],
  options: { address: [Getter/Setter], jsonInterface: [Getter/Setter] },
  defaultAccount: [Getter/Setter],
  defaultBlock: [Getter/Setter],
  methods:
   { setWord: [Function: bound _createTxObject],
 '0xcd048de6': [Function: bound _createTxObject],
 'setWord(string)': [Function: bound _createTxObject],
 getWord: [Function: bound _createTxObject],
 '0xed40a8c8': [Function: bound _createTxObject],
 'getWord()': [Function: bound _createTxObject] },
  events: { allEvents: [Function: bound ] },
  _address: null,
  _jsonInterface:
   [ { constant: false,
   inputs: [Object],
   name: 'setWord',
   outputs: [Object],
   payable: false,
   type: 'function',
   stateMutability: 'nonpayable',
   signature: '0xcd048de6' },
 { constant: true,
   inputs: [],
   name: 'getWord',
   outputs: [Object],
   payable: false,
   type: 'function',
   stateMutability: 'view',
   signature: '0xed40a8c8' } ] }

Answer 1

Your code should look like this:

// Note no "new" on the next line, and the lowercase "contract"
var contract = web3.eth.contract(JSON.parse(data.abi), data.address);
contract.getWord.call((err, result) => {
    if (err) {
        // handle error here
    }
    else {
        // use result here, console.log it to see the structure
    }
});

Answer 2

With the latest version of Web3, you simply call

var contract = new web3.eth.Contract(JSON.parse(data.abi), data.address);
const result = await contract.getWord().call();